The Haber and Contact Processes

·         The raw materials that are needed are Nitrogen from the air, and hydrogen from natural gas or cracking hydrocarbons

·         Conditions for the Haber Process 

§   - 450°C 

§  200 atmospheres (atm)

§  Iron catalyst

·         Reaction is reversible

·         Forward reaction is exothermic (gives out heat)

                                        N₂ + 3H₂ ⇌ 2NH₃

·         Decreasing temperature will increase yield but the reaction is still done at high temperatures to speed up the rate of reaction, and it is also quicker (time is money)

·         Uses of Ammonia

•  
  •  
    • Nitric Acid
    • Fertilisers

·         Test - Turns damp red litmus paper blue

Stage 1 - The Mixer

The nitrogen and hydrogen are fed into the mixer where they are mixed and cleaned

Stage 2 - The Compressor

The mixed gases are compressed to a pressure of about 200 atmospheres (atm)

Stage 3 - The Converter

The gases are heated to about 450 degrees celcius. The gases pass over iron catalysts, where they react to form ammonia

Stage 4 - The Cooler

The ammonia, and unreacted nitrogen and hydrogen move into the cooler

Stage 5 -

Unused gases are recycled to try and become ammonia

Temp - 450 degrees celcius                 Pressure - 2 atmospheres

Catalyst - Vanadium

1) Burn sulfur which creates sulfur dioxide

      S + O --- SO2

2) Sulfur dioxide is oxidised to form sulfur trioxide

      2SO2 + 02 --- 2SO3

3) Sulfur trioxide is dissolved in concentrated sulfuric acid to form a liquid oleum

      SO3 +H2S04 --- H2S207

4) Oleum is diluted, which makes it less dangerous, with water to form concentrated sulfuric acid

      H2S2O7 +H20 --- 2H2SO4